The Lyman Alpha Forest in PKS 2126--158 at 8 ${\bf km\,s^{-1}}$ Resolution
Session 90 -- Absorption in AGN Spectra
Oral presentation, Friday, January 14, 10:15-11:45, Salon IV Room (Crystal Gateway)

## [90.02] The Lyman Alpha Forest in PKS 2126--158 at 8 ${\bf km\,s^{-1}}$ Resolution

Michael J. Keane (UCO/Lick Observatory)

The high redshift quasar PKS 2126--158 ($z_{em} = 3.27$) was observed with the high resolution echelle spectrometer (HIRES) on the Keck telescope. A spectrum covering the wavelength range 3500{\AA}--7000{\AA}, corresponding to 820{\AA}--1640{\AA} in the quasar's rest frame, was obtained at a resolving power of $R = 34,000$, a velocity resolution of 8.6 ${\rm km\,s^{-1}}$. The signal to noise ratio in this spectrum exceeds 50 near 5000{\AA} and is better than 30 in the region between Ly\,$\alpha$ and Ly\,$\beta$ at $z=3.27$. A list of absorption features with column densities and Doppler parameters ($N$ \& $b$) derived from fitting to the line profiles is given.

A sample of ${\rm Ly} \,\alpha$ lines that is complete to $\log N_{\rm HI} < 13.0$ is constructed. An analysis of this ${\rm Ly} \,\alpha$ sample is presented including the effects of line blending in the Lyman alpha forest, the intrinsic column density and Doppler parameter distribution functions and the apparent $b$--$N_{\rm HI}$ correlation.

Three heavy element absorption systems with $z_{abs} > 2.3$ are studied in detail. Each system displays complex velocity structure with multiple components extending up to $\Delta v \sim 270\, {\rm km\,s^{-1}}$. The relative strengths of the individual components in each system varies from species to species, with both high and low ionization components present. Implications for the ionization state, abundance and origin of the metal-line systems are discussed.